﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp2
{
    class zheng:xingzhuang
    {
        double a;
        public double A
        {
            get { return this.a; }
            set { this.a = value; }
        }
        public virtual void GetArea(double a)
        {
            double s = a * a;
            Console.WriteLine(s);
        }
    }
}
